Method for generating and maintaining a glow plasma discharge

Abstract

A method and apparatus for stabilizing glow plasma discharges by suppressing the transition from glow-to-arc includes a perforated dielectric plate having an upper surface and a lower surface and a plurality of holes extending therethrough. The perforated dielectric plate is positioned over the cathode. Each of the holes acts as a separate active current limiting micro-channel that prevents the overall current density from increasing above the threshold for the glow-to-arc transition. This allows for a stable glow discharge to be maintained for a wide range of operating pressures (up to atmospheric pressures) and in a wide range of electric fields include DC and RF fields of varying strength.

What is claimed is: 
     
       1. A method of stabilizing glow-to-arc transition for a discharge plasma comprising the steps of: positioning electrodes in facing relation;   providing a perforated dielectric having a plurality of current limiting micro-channel apertures therethrough for limiting current density from increasing above glow-to-arc transition; and   covering one of the electrodes with the perforated dielectric.   
     
     
       2. The method of claim 1 further comprising the step of covering the other of the electrodes with a perforated dielectric having a plurality of current limiting micro-channel apertures so that both electrodes are covered. 
     
     
       3. The method of claim 1 wherein the step of covering one of the electrodes comprises placing a dielectric material thereon and retaining the dielectric material thereon. 
     
     
       4. The method of claim 3 wherein the state of retaining the dielectric material on one of the electrodes further includes the step of securing a retaining collar having an upper surface with a cylindrical aperture extending therethrough, and sidewalls depending therefrom, over the dielectric. 
     
     
       5. The method of claim 1 wherein the step of covering one of the electrodes comprises the step of depositing a dielectric on one of the electrodes. 
     
     
       6. The method of claim 5 wherein the step of depositing a dielectric on one of the electrodes comprises vapor deposition. 
     
     
       7. A method of generating and maintaining a glow plasma discharge comprising: positioning opposing electrodes in a facing relationship with a space therebetween;   providing a dielectric;   forming a plurality of apertures sized to limit current density from increasing above glow-to-arc transition;   positioning the dielectric between the opposing electrodes to partially occupy the space therebetween; and   generating an electric field between the opposing electrodes.   
     
     
       8. The method of claim 7 further comprising providing a second dielectric and forming a plurality of apertures sized to limit current density from increasing above glow-to-arc transition and positioning the second dielectric in the space between the opposing electrodes. 
     
     
       9. A method of generating and maintaining a glow plasma discharge comprising: providing a first electrode;   depositing a dielectric on the first electrode to form a plurality of apertures of micron dimensions sized to limit current density from increasing above glow-to-arc transition;   providing a second electrode in facing relation to the first electrode; and   generating an electric field between the electrodes.   
     
     
       10. The method of the claim 9 wherein the apertures are formed to have a diameter ranging from 5 to 200 microns. 
     
     
       11. The method of claim 8 further comprising the step of arranging the plurality of apertures such that the center to center distance is of the same level of dimension as the size of the apertures. 
     
     
       12. The method of claim 11 wherein the step of forming a plurality of apertures is performed by laser abolition. 
     
     
       13. The method of claim 12 wherein the apertures are sized to be 10 microns and the apertures are arranged such that the center to center distance between apertures is 12 microns. 
     
     
       14. The method of claim 12 wherein the apertures are sized such that the aperture diameter to dielectric thickness ratio is 10 to 1. 
     
     
       15. The method of claim 14 wherein the apertures are sized to be 5 to 200 microns and the thickness of the dielectric is between 100 microns and 2 millimeters.